Duramax '03 owners-advice Please

r4man2

Member
We are preparing for towing a 3400RL and the subject of transmission coolers came up. I will be within towing guidelines and will be towing with an '03 2500HD with D/A. I have a Banks exhaust, aftermarket air intake, Edge Juice and intend to use Highest grade Amsoil products.

Do I need a tranny cooler? I expect we will do lots of mountain towing but we will take our time.

Also, does anyone out there use the Amsoil bypass oil filter? How about extra fuel filters?

"...'cause we can only afford to do it once. No second tries!"
 

ChopperBill

Well-known member
Spent more time towing in the mountains than on the plains. The Allison is set up perfect. No worries. GM and Allison did their home work. It is a transmission that most manufactures want to duplicate.
on edit: I don't have any other optional filters. The new 2 micron fuel filters seem good enough for GM to warranty the injectors for 200,000 miles and that is good enough for me. I would leave the bypass filters for the big rigs. No sense in spending money that isn't needed. I only use dinosaur oil, thats what comes in it.
 

ct0218

Well-known member
No need for an additional transmission cooler. I use Amsoil and the bypass system and have used both for many, many years.
 

fishn2dmax

Well-known member
I have a 2003 GMC 2500HD CC Duramax / Allison and there is no need for additional cooling additions to that tranny! I can attest to pulling 15,000 up 6-7% grades in the rockies ( at interstate speeds) and the allison never got near it's hot zone. EGT's ( exhaust gas temps) are something you should be more concerned with on hot days or when pulling long grades under heavy load. On my Juice edge, I run level 1 or stock setting while towing and rarely ever have the EGT's exceeded 1300 degrees. If you set your juice box at level 2 or higher, you will likely exceed the max EGTs. My Juice attitude monitor has an alarm that let's me know when I'm close to exceeding a number of user selected max parameters including: Tranny temp, EGT's, and speed.
 

Uncle Rog

Well-known member
I agree with Chopper on the Duramax / Allison combo. I have pulled the Grapevine above LA in August and Ibex pass outside of Death Valley (NOT in August) and I would not change a thing on my rig. The 100k drive train warranty sold me too start with and have never felt under powered. Chopper, what the hey is dinosaur oil?
 

cjbearden

Visitor
Hopefully Chopper means Sinclair oil with the dino logo. Be awfully hard to wrangle them dinosaurs now days!:D
 
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Chulinw

Guest
r4man2 I went to the local Allison dealer and ordered the large Allison pan and filter replacement. It cost around $75.00 for both and then I change all the transmission fluid to Amsoil. I think it adds 3 quarts extra fluid for the transmission. Not a hard job. It took about two hours to do everything. I never had an over heating problem just want to be on the safe soide. The amsoil cost for 5 gal was around $160.00.
 

bsnider

BS & Ruth Ann
Watch out for Ford

I have a 2002 Ford F350 which is getting a new transmission. The cooler on this truck was the same as what they put on a F150. All of the weight data for this truck shows that I have the ability to pull my 7 ton trailer, but, I didn't. I will now, after my $3000 bill.
 

billd

Well-known member
bsnider,

You can also help your tranny by installing a trans cooler from a 6.0 PSD truck. The mount points are the same, but you get a 25 row cooler vs a 9 row cooler that was installed on the 7.3.

Bill D.
 

snuffy

Well-known member
Dino oil is conventional non-synthetic oil. I use Chevron Delo 400 15W40 in my Duramax and have oil analysis done occassionally. I live in a reasonaby mild winter climate and feel I don't need synthetic. My car has 330,000 miles on it all on Havoline 10W30 with 5000 mile oil change intervals and the inside are very clean.
 
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